Method for refining a metal and corresponding station

Abstract

The method and corresponding station (10) for refining metals in a steel plant includes a degassing device (11) and a monitoring device (100), the monitoring device (100) having a gas analyzer (101), one or more pressure detectors (103), possibly one or more flow detectors (104) and a processing unit (102).

Description

Technical Field

[0001] This invention relates to a method for refining metals and a corresponding station, which can be applied to the steel industry and steel production field, such as the field of secondary metallurgical processes for steel, and can also be applied to the field of processing other metals, in which ladle furnaces, refining furnaces, vacuum degassing treatment stations, etc. exist. Background Technology

[0002] In secondary metallurgical processes, especially in the production of so-called special steels, refining is known to be performed, partly in an electric arc furnace (EAF), but more commonly directly in a subsequent ladle furnace (LF), and where possible in an additional vacuum degassing station.

[0003] The LF furnace is equipped with a furnace cover. At the end of refining, electrodes can be lowered through the furnace cover to heat the metal. The degassing station includes an airtight chamber in which the ladle can be placed. Alternatively, the degassing station is equipped with a furnace cover that can airtightly isolate the ladle, thereby creating a vacuum environment inside the ladle.

[0004] Refining typically includes deoxidation, alloying, desulfurization, vacuum degassing (VD), vacuum oxygen decarburization (VOD), and inclusion removal to fine-tune the chemical composition so that it falls within the range of chemical species specified in the technical specifications of the steel grade to be produced. The refining process requires a high degree of homogenization of the molten metal in terms of both chemical composition and temperature.

[0005] Homogenization is achieved by continuous stirring, which can be carried out by injecting an inert gas (such as argon or nitrogen). The device used is an immersion spray gun or a permeable brick set at the bottom of the ladle and connected to the gas injection line. The purpose is to continuously stir the molten metal pool and cause solid and / or gaseous inclusions and impurities present in the pool to float to the surface.

[0006] Starting with the initial chemical composition, the desired chemical composition of the metal can be achieved through operational procedures (such as adding ferroalloys, vacuum treatment, etc.) developed based on statistical analysis of past production or experimental studies.

[0007] Because thermochemical processes are affected by many parameters and have significant fluctuations, it is necessary to collect subsequent samples to verify the deviations between the concentrations of each chemical component in the metal and the expected values, and to make corrections to subsequent actions if possible.

[0008] Because of the large number of independent parameters, and the fact that the calibration parameters among these parameters are highly dependent on the production equipment used and do not remain constant over time, the application of the correlations described in the literature and / or the above-mentioned operating procedures cannot always calculate the current values ​​of chemical components in the refining process. Therefore, it is necessary to use physical and / or statistical models to help estimate the concentration values ​​of chemical components in the metal in real time.

[0009] Typically, the above models are based on process data collected over time, such as pressure on the surface of the molten metal pool, gas flow rate from permeable bricks or immersion lances, and measurements of the chemical concentrations of various elements dissolved in the molten pool. The chemical concentrations achieved are usually measured "point-by-point" (non-continuously), for example, in a laboratory setting. Even when using automated samplers, this method still involves the use of consumables (sampling cartridges) and requires manual labor.

[0010] The measurement of dissolved chemical components in molten steel is performed by sampling the molten steel, allowing it to solidify, and then measuring it in the laboratory using a mass spectrometer. Mass spectrometry can identify specific elements and compounds, such as carbon, nitrogen, oxygen, aluminum, silicon, phosphorus, sulfur, titanium, vanadium, chromium, manganese, iron, nickel, and copper. Conversely, the measurement of hydrogen content in molten steel is typically performed using instruments based on TCD (thermal conductivity detector) technology, equipped with appropriate consumables, and introduced into the molten pool. In the latter case, no material sample collection is provided, and analysis is performed using on-site instruments.

[0011] However, due to the characteristics of vacuum processing equipment (such as VD, VOD, etc.), it is difficult to perform measurements of the chemical composition dissolved in liquid steel during the vacuum stage, because the ladle is inserted into a chamber that is airtightly isolated by a furnace lid, or the ladle is directly airtightly isolated by its furnace lid.

[0012] When steel mills are equipped with vacuum samplers, measurements can be performed directly, but this incurs higher costs, including for the steel mill itself (CAPEX costs) as well as for higher maintenance costs and higher consumable usage (OPEX costs). Furthermore, in these cases, the steel mill's efficiency can decrease due to larger erroneous gas leaks.

[0013] US2012 / 0266722 describes a method and apparatus for degassing molten metal in a melting chamber, wherein the method and apparatus are provided to measure the concentration distribution of gases (particularly CO and CO2) in the furnace using an adjustable laser source, an optical detector and a reference detector.

[0014] Therefore, there is a need to improve a method and corresponding equipment for refining liquid metals that can overcome at least one of the defects of existing technologies.

[0015] Therefore, it is necessary to determine the progress of the degassing process and to estimate in real time the content of dissolved hydrogen, nitrogen, carbon, sulfur and other possible chemical components in the molten metal pool.

[0016] One object of the present invention is to improve a method for refining metals and to provide a metal refining station that can estimate in real time the content of dissolved hydrogen, nitrogen, carbon, sulfur and other possible chemical components in the molten metal pool in a sufficiently accurate manner.

[0017] Another object of the present invention is to improve a method for refining metals and to provide a corresponding station for refining metals, which can reduce the volatility of refining processes by knowing their state before interrupting the process.

[0018] One object of the present invention is to provide a monitoring device for a metal refining station.

[0019] Another objective of this invention is to interrupt or extend the vacuum processing process based on a reliable estimate of the process status, thereby saving time / energy and reducing production costs compared to existing refining processes.

[0020] Another objective of this invention is to reduce the hardware cost of process gas analysis in vacuum processing.

[0021] The applicant designed, tested, and implemented this invention to overcome the deficiencies of the prior art and achieve the above and other objectives and advantages. Summary of the Invention

[0022] The invention is set forth and characterized in the independent claims, while the dependent claims describe other features of the invention or variations of the main inventive concept.

[0023] In order to achieve the above objectives and to solve the aforementioned technical problems in a novel and original manner, and to realize significant advantages over the prior art, the following discloses a method for refining metals in a refining station in a steel plant according to the present invention.

[0024] According to one aspect of the invention, the refining station includes a degassing device. The degassing device can be operated under vacuum.

[0025] According to one aspect of the invention, the refining station may include one or more vacuum chambers.

[0026] According to one aspect of the present invention, the method specifies that: - Position the gas analyzer of the monitoring equipment downstream of the dust separator of the dust filtration unit of the degassing equipment; - The monitoring device detects the chemical concentration of one or more chemical components in the process gas drawn into the degassing equipment; - Detect the ambient pressure near the surface of the molten metal pool; - The concentration of one or more chemical components dissolved in the molten metal pool is estimated in real time based on the concentration of one or more chemical components in the process gas and the pressure mentioned above.

[0027] Thus, compared to existing operational practices that provide processing instructions based on processing time and parameters limited by statistical considerations, this method advantageously allows for the real-time estimation of the content of more than one chemical component (e.g., hydrogen and nitrogen) in the molten metal pool by measuring the chemical concentration of more than one chemical component in the process gas in real time. In this way, the degassing process can be terminated at an appropriate time, and the concentration of the chemical component in the metal can be estimated with good reliability as the desired concentration.

[0028] This shortens the processing time. More importantly, it avoids the need to restore the vacuum when it is recognized that the desired concentration value has not been reached, which would require significantly longer processing times (at least 10-15 minutes longer in a processing time of about half an hour), increased energy consumption to return the molten metal pool to low pressure, and reduced time for the decantation step.

[0029] According to another aspect of the invention, the method can be specified as follows: the analyzer is positioned downstream of the pump unit of the degassing equipment. Advantageously, after the pump unit, the process gas is substantially at ambient pressure and a temperature below 100°C. Furthermore, the dust content in the process gas is minimized.

[0030] According to another aspect of the present invention, the method may specify that the analyzer is selected from a mass spectrometer, a Fourier transform infrared spectrometer (FTIR) spectrometer, a Raman spectrometer, or a thermal conductivity detector (TCD).

[0031] According to another aspect of the present invention, the method may specify that the analyzer is a Raman spectrometer gas analyzer.

[0032] Advantageously, the use of RAMAN-based gas analyzers allows for the analysis of most process gases in metal refining processes with high reliability. For example, CO, CO2, H2, N2, O2, and CH4 can be measured.

[0033] Furthermore, compared to, for example, a mass spectrometer, using an analyzer as described above allows for lower equipment and maintenance costs. In fact, mass spectrometers have very high costs that are difficult to amortize over time.

[0034] According to another aspect of the invention, the method may specify that, in order to calculate the concentration of one or more chemical components dissolved in the metal, a calculation model is used, which takes the chemical concentration of one or more chemical components in the process gas and the ambient pressure corresponding to the surface of the molten metal pool as input parameters.

[0035] According to another aspect of the invention, the method may specify that, in a preliminary step, a calculation model is defined based on data generated from punctual analysis of the concentration of chemical components dissolved in the molten metal pool and the concentration values ​​of one or more chemical components in the corresponding process gas calculated based on measurement data detected by a gas analyzer.

[0036] According to another aspect of the invention, the method may specify: detecting the flow rate of the stirring gas in the molten metal pool and using it in conjunction with the concentration and pressure of one or more chemical components to estimate the concentration of one or more chemical components dissolved in the metal.

[0037] According to another aspect of the invention, the method may specify that the chemical component is one or more of hydrogen or nitrogen.

[0038] According to another aspect of the invention, the method can provide an extraction mode for a sample of the process gas, which provides extraction from the device's suction line. In this way, the gas can be adjusted for temperature, dust content, and / or humidity, if desired.

[0039] According to another aspect of the invention, the method can alternatively provide an in-situ mode that performs measurements of the process gas flow rate in the suction line directly via a coupling element. For example, in the case of a Raman spectrometer, the coupling element allows both monochromatic electromagnetic radiation and the measurement electromagnetic radiation to pass through.

[0040] In this way, measurements can be performed directly in conjunction with the suction line without the need to sample the process gas.

[0041] According to another aspect of the invention, the station in the refinery used for refining metals includes degassing equipment and monitoring equipment.

[0042] The monitoring equipment includes a gas analyzer located downstream of the dust separator in the dust filtration unit of the degassing equipment.

[0043] The device is configured to detect the concentration of one or more chemical components in the process gas being drawn into the degassing equipment and the ambient pressure corresponding to the surface of the molten metal pool, and to estimate the concentration of one or more chemical components dissolved in the molten metal pool in real time based on the concentration of one or more chemical components in the process gas and the pressure.

[0044] According to another aspect of the invention, the monitoring device includes one or more pressure detectors and a processing unit.

[0045] According to another aspect of the invention, the analyzer may be a Raman spectroscopy gas analyzer, which includes a coupling element that allows the electromagnetic radiation that excites the Raman spectrum and the electromagnetic radiation that is measured to pass through, so as to directly measure the process gas flow rate in the process gas extraction line.

[0046] According to another aspect of the invention, the secondary steelmaking plant for refining metals includes one or more LF furnaces and one or more metal refining stations, or VD / VOD stations. Attached Figure Description

[0047] These and other aspects, features, and advantages of the invention will become apparent from the following description of some embodiments given by way of non-limiting examples with reference to the accompanying drawings, in which: - Figure 1 This is a schematic diagram of a metal refining station according to the present invention; - Figure 2 yes Figure 1 A schematic diagram of the monitoring equipment at a metal refining station; - Figure 3 It shows from Figure 2 Raman spectra obtained by the gas analyzer of the monitoring equipment.

[0048] We must clarify that the wording and terminology used in this specification, as well as the figures in the accompanying drawings which are also related to how the invention is described, serve only to better illustrate and explain the invention. Their purpose is to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0049] For ease of understanding, the same reference numerals are used to identify the same common elements in the figures where possible. It should be understood that elements and features of one embodiment can be readily combined or incorporated into other embodiments without further explanation. Detailed Implementation

[0050] Reference Figure 1 According to the present invention, a metal refining station 10 in a steel plant for producing metallic materials (e.g., steel) includes a degassing device 11 and a monitoring device 100 configured to determine the progress status of the metal degassing process.

[0051] The station 10 may include one or more vacuum chambers 12.

[0052] One or more vacuum chambers 12 may each include: a container 13 having an upper orifice 14 and a cover 15 that can be hermetically associated with the container 13, within which the ladle 50 is housed. In an alternative embodiment not shown here, the vacuum chamber may include a cover that engages with an orifice in the ladle and can be hermetically closed during use, thus eliminating the need for a container.

[0053] The ladle 50 is a cylindrical container with a closed base and lined with refractory material. It is designed to contain the molten metal pool M generated in a furnace (such as an electric arc furnace EAF) and transport it downstream for subsequent refining and finally continuous casting.

[0054] The ladle 50 is provided with an open upper part 51 and at least one permeable brick or immersion spray gun 52, which passes through the bottom wall 53 of the ladle 50, through which gas (preferably inert gas) is blown, thereby ensuring the stirring of the contained molten metal pool M.

[0055] The degassing device 11 is capable of extracting process gases present in the environment corresponding to the molten metal pool M, such as those corresponding to or near its surface. For example, the degassing device 11 is capable of extracting process gases from more than one vacuum chamber 12.

[0056] The degassing device 11 can operate under vacuum. Therefore, it is suitable for vacuum processing, i.e., generating pressures significantly lower than the ambient pressure within the vacuum chamber 12 during operation. In this case, at least in some processing steps, the pressure corresponding to the surface of the molten metal pool M can be negative relative to the ambient pressure.

[0057] Vacuum treatment can be performed during refining to achieve the desired temperature of the molten metal pool M being processed, to achieve the desired content of dissolved chemical components (e.g., hydrogen and nitrogen), and the desired content of elements (e.g., sulfur and carbon) in the molten metal pool M.

[0058] The degassing device 11 may include a dust filtration unit 20 to separate dust from the process gas. The dust filtration unit 20 may include a dust separator 21 and possible additional filtration devices 22, such as a cyclone separator and / or a bag filter.

[0059] The degassing device 11 may include multiple pipes 25, 26, 27, 28 to form a fluid-connected suction line 29 for various components of the degassing device 11. It may also include a vacuum pump unit 30, such as a mechanical pump or a steam ejector, to generate a vacuum and expel the process gas.

[0060] Specifically, pipe 25 can connect one or more vacuum chambers 12 to dust separator 21; pipe 26 can connect dust separator 21 to any subsequent filter device 22 or pump unit 30; pipe 27 can connect filter device 22 to pump unit 30; and pipe 28 can connect pump unit 30 to the outlet of process gas.

[0061] Degassing device 11 may also include: - A steering mechanism 31 that allows selection of the vacuum chamber 12 to operate on when more than one (usually two) of the vacuum chamber 12 is required; - Main shut-off valve 32, which separates the vacuum chamber 12 side from the pump unit 30 side in order to reduce the time required to reach a vacuum; - Cooler, which cools the flue gas.

[0062] The device 100 is used to determine the progress of the degassing process of the molten metal pool M by estimating in real time the content of one or more chemical components dissolved in the metal, wherein the chemical components are in particular gases, such as hydrogen and nitrogen, and also oxygen, carbon, sulfur, etc.

[0063] Device 100, or at least its measuring portion, is located downstream of dust separator 21. Therefore, device 100 can be positioned corresponding to pipe 26 at the outlet of dust separator 21.

[0064] According to one embodiment, in the presence of an additional filtration device 22, the device 100 may be positioned downstream of the dust filtration unit 20.

[0065] According to another embodiment, device 100 may be located downstream of pump unit 30.

[0066] The device 100 includes a gas analyzer 101 and a data processing unit 102.

[0067] The device 100 may include one or more pressure detectors 103 for detecting the ambient pressure corresponding to the molten metal pool M. For example, the pressure detectors 103 may be positioned to detect the pressure in one or more vacuum chambers 12 or near the ladle 50. Data detected by one or more pressure detectors 103 can be acquired by the processing unit 102.

[0068] The device 100 may include one or more flow detectors 104 for measuring the flow rate of the stirring gas. Data detected by the one or more flow detectors 104 may be acquired by the processing unit 102.

[0069] The device 100 may include one or more temperature detectors for detecting the temperature of the molten metal pool M. Data detected by the one or more temperature detectors may be acquired by the processing unit 102.

[0070] The analyzer 101 can be selected from mass spectrometers, Fourier transform infrared spectrometers (FTIR spectrometers), RAMAN spectrometers, thermal conductivity detectors (TCD), etc.

[0071] Preferably, the analyzer 101 is a Raman spectroscopy gas analyzer. In this case, the analyzer 101 may include methods for generating excitation electromagnetic radiation R1 (…). Figure 2The laser device 120. The electromagnetic radiation R1 can be monochromatic and collimated.

[0072] In a known manner, electromagnetic radiation R1 is in the frequency range of visible light or IR (infrared), preferably in the visible light range.

[0073] The wavelength of electromagnetic radiation R1 can be defined based on the chemical component to be detected; for example, it can be 532 or 785 nm.

[0074] The analyzer 101 may include an optical fiber (not shown) for transmitting electromagnetic radiation R1 to the measurement point where the process gas to be measured is located.

[0075] The analyzer 101 is configured to irradiate the process gas drawn into the degassing unit 11 with electromagnetic radiation R1. After being excited by electromagnetic radiation R1, the process gas can emit measuring electromagnetic radiation R2.

[0076] Analyzer 101 may include instruments for analyzing and measuring electromagnetic radiation R2 and generating Raman spectra SR ( Figure 3 ) spectrometer 121 ( Figure 2 ).

[0077] The analyzer 101 may include an optical fiber (not shown) for transmitting the measured electromagnetic radiation R2 from the process gas to the spectrometer 121.

[0078] The measured radiation R2 includes Raman-scattered electromagnetic radiation.

[0079] Analyzer 101 may include ( Figure 2 The system includes multiple optical elements for processing radiation R1 and R2, such as filters 125 and 126 for filtering the bands of interest of radiation R1 and R2, focusing lenses 127 and 128, a dichroic mirror 129, a collimating mirror 130, a diffraction grating 131 for separating radiation R2 into its constituent wavelengths, a focusing mirror 132, and a CCD (charge-coupled device) detector 133.

[0080] The analyzer 101 may include a receiving chamber 135 ( Figure 2 The analyzer 101 is used to contain the sample to be analyzed in an extraction measurement mode, which provides extraction and transport of the gas sample into the containment chamber 135. Therefore, the analyzer 101 may include a sampler (not shown) or work in conjunction with a sampler for acquiring and delivering samples of process gases.

[0081] Gas samples can be extracted corresponding to pipes 26 or 27 and conditioned to suitable temperature, dust content, and humidity conditions for measurement. Alternatively, gas samples can advantageously be extracted downstream of pump unit 30, corresponding to pipe 28.

[0082] Alternatively and as Figure 1 As shown, the analyzer 101 includes a coupling element 136 for coupling with the suction line 29 for in-situ analysis. The coupling element 136 may be an optical window that allows excitation radiation R1 and measurement radiation R2 to pass through.

[0083] Analyzer 101 provides digital measurement data related to the Raman spectrum SR at the output, which can be obtained, for example, through a graph of the Raman spectrum SR. Figure 3 The above measurement data can be obtained through the processing unit 102.

[0084] Specifically, for each chemical component (e.g., hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide), there are one or more corresponding peaks in the Raman spectrum (SR). Each peak corresponds to the vibrational mode of the corresponding chemical component's molecule.

[0085] The processing unit 102 is configured to estimate the gas content in the molten metal pool M.

[0086] The processing unit 102 may include a processing module 140 and a storage module 141. It may also include a module 142 for interfacing with components of the station 10 and / or a device 143 for interfacing with an operator.

[0087] The processing module 140 may be a local or remote (e.g., in the cloud) microcontroller, microprocessor, processor, etc.

[0088] The processing module 140 can be implemented as a whole as an algorithm for acquiring, managing and processing measurement data.

[0089] For example, the algorithm described above can be configured for the acquisition, management, and processing of Raman spectra (SR).

[0090] Data processing algorithms can calculate the chemical concentration of one or more chemical components in process gases based on measurement data. For example, and preferably, they can calculate the chemical concentrations of hydrogen and nitrogen, but they can also calculate the concentrations of oxygen, carbon monoxide, carbon dioxide, methane, etc.

[0091] In another embodiment, the chemical concentration of one or more chemical components in the process gas based on the measurement data can be calculated by the analyzer 101, for example in the data processing module of the analyzer 101.

[0092] The data processing algorithm may include a computational model that takes the chemical concentration of the chemical components in the process gas and the ambient pressure corresponding to the molten metal pool M as input parameters. The flow rate and / or temperature of the stirring gas may also be input parameters to the model.

[0093] In the preliminary steps, a calculation model can be defined based on data generated from point-to-point analysis of the concentration of chemical components dissolved in the molten metal pool M and the chemical concentration values ​​of one or more chemical components in the process gas calculated based on the corresponding measurement data.

[0094] The term "corresponding" refers to its association with the molten metal pool M to which the point analysis is performed. Point analysis is understood to be performed by obtaining more than one sample of the material from the molten metal pool M and analyzing them, for example, using field or laboratory instruments. Preparatory steps may be experimental steps, or preferably, they may be performed during more than one previous processing cycle.

[0095] The processing module 140 can also, as a whole, implement algorithms for the automatic management and control of the functions of station 10 through interface module 142. For example, based on the results of measurement data processing, when the estimated concentration of chemical components (e.g., hydrogen, nitrogen) in the molten metal pool M has reached the desired value, the processing module 140 can command the vacuum processing to end. As another example, it can provide data to the operator through interface device 143.

[0096] Storage module 141 can be one or more of commercially available storage devices, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, mass storage, or any other form of digital storage, whether local or remote.

[0097] The storage module 141 is capable of storing the above-mentioned data acquisition, management and processing algorithms, as well as the above-mentioned management and command algorithms, and the acquired and estimated data.

[0098] Module 142, which is used to interface with components of station 10, may include data transmission devices, actuation systems, etc.

[0099] The device 143 for interfacing with the operator may include a screen, audio equipment, keyboard, mouse, etc.

[0100] The operation of the above-described device 10 corresponding to the method according to the present invention includes the following steps: - Position the gas analyzer 101 downstream of the dust separator 21; - The chemical concentration of one or more chemical components in the process gas drawn into the degassing equipment 11 is detected by the monitoring equipment 100; - Detect the ambient pressure near the surface of the molten metal pool M; - The concentration of one or more chemical components dissolved in the molten metal pool M is estimated in real time based on the above-mentioned concentration and pressure of one or more chemical components in the process gas.

[0101] This method can specify that the gas analyzer 101 is positioned downstream of the pump unit 30.

[0102] This method can specify that: analyzer 101 is a Raman spectrometer gas analyzer.

[0103] The method may specify that a computational model is used for the above estimation, which takes the chemical concentration of one or more chemical components in the process gas, the ambient pressure corresponding to the surface of the molten metal pool M, and, where possible, the flow rate and / or temperature of the stirring gas as input parameters.

[0104] Therefore, this method can specify that: a preliminary fixed-point analysis is performed on the chemical components dissolved in the liquid metal molten pool M, the concentration values ​​of one or more chemical components in the process gas are calculated based on the measurement data of the analyzer 101, and a model is defined by correlating the values ​​obtained from the above fixed-point analysis and the above concentration values ​​in the process gas.

[0105] This method can specify that the analyzer 101 should be calibrated.

[0106] Obviously, modifications and / or additions can be made to the station 10, the device 100, and the method as described above without departing from the scope and range of the invention as defined by the claims.

[0107] It is equally apparent that, although the invention has been described with reference to some specific examples, those skilled in the art will be able to implement other equivalent forms of methods and corresponding stations for refining metals, which have the characteristics set forth in the claims, and thus all fall within the scope of protection defined therein.

[0108] In the following claims, the reference numerals in parentheses are for the sole purpose of facilitating their reading and shall not be considered as limiting factors with respect to the scope of protection defined by the claims.

Claims

1. A method for refining metals in a refining station (10) of a steel plant, said refining station (10) comprising a degassing device (11), characterized in that, The method specifies that: - Position the gas analyzer (101) of the monitoring device (100) downstream of the dust separator (21) of the dust filter unit (20) of the degassing device (11); - The chemical concentration of one or more chemical components in the process gas drawn into the degassing device (11) is detected by the monitoring device (100); - The ambient pressure near the surface of the molten metal pool (M) is detected by one or more pressure detectors (103); - The concentration of one or more chemical components dissolved in the molten metal pool (M) is estimated in real time by using the concentration of one or more chemical components in the process gas and the pressure.

2. The method according to claim 1, characterized in that, The method specifies that the analyzer (101) is positioned downstream of the pump unit (30) of the degassing device (11).

3. The method according to claim 1 or 2, characterized in that, The analyzer (101) is selected from mass spectrometer, Fourier transform infrared spectrometer (FTIR) spectrometer, RAMAN spectrometer, and thermal conductivity detector (TCD).

4. The method according to claim 1 or 2, characterized in that, The method specifies that the analyzer (101) is a Raman spectrometer gas analyzer.

5. The method according to any one of claims 1 to 4, characterized in that, The method specifies the use of a computational model that takes the chemical concentration of one or more chemical components in the process gas and the ambient pressure corresponding to the surface of the molten metal pool (M) as input parameters, and wherein, in the preparatory step, the computational model is defined based on data generated from point-source analysis of the concentration of chemical components dissolved in the molten metal pool and the concentration values ​​of one or more chemical components in the corresponding process gas.

6. The method according to any one of claims 1 to 5, characterized in that, The method specifies that the flow rate of the stirring gas in the molten metal pool (M) is detected and used in conjunction with the concentration and pressure of one or more chemical components in the process gas to estimate the concentration of the one or more chemical components dissolved in the molten metal pool (M).

7. The method according to any one of claims 1 to 6, characterized in that, The method specifies that the chemical component is one or more of hydrogen or nitrogen.

8. The method according to any one of claims 1 to 7, characterized in that, The method provides a selection of an extraction mode or an in-situ mode for a sample of the process gas, the extraction mode providing extraction from the suction line (29) of the degassing device (11), and the in-situ mode providing direct measurement of the flow rate of the process gas in the suction line (29).

9. A station (10) for refining metals in a steel plant, the station (10) comprising a degassing device (11) and a dust separator (21) of a dust filtration unit (20) of the degassing device (11), characterized in that, The station (10) also includes a monitoring device (100) downstream of the dust separator (21), the monitoring device (100) including a gas analyzer (101) located downstream of the dust separator (21) of the dust filtration unit (20) of the degassing device (11), the device (100) including the gas analyzer (101) and one or more pressure detectors (103), the gas analyzer (101) being configured to detect the concentration of one or more chemical components in the process gas drawn from the degassing device (11), the one or more pressure detectors (103) being configured to detect the ambient pressure corresponding to the surface of the molten metal pool (M) and to estimate in real time the concentration of one or more chemical components dissolved in the molten metal pool (M) by means of the concentration of one or more chemical components in the process gas and the pressure.

10. The station (10) according to claim 9, characterized in that, The analyzer (101) is a Raman spectroscopy gas analyzer, including a laser device (120) and a spectrometer (121). The laser device (120) is used to generate electromagnetic radiation (R1), which excites measurement electromagnetic radiation (R2) emitted by the process gas. The spectrometer (121) is used to detect and analyze the measurement electromagnetic radiation (R2) and generate a corresponding Raman spectrum (SR). The processing unit (102) is configured to command the analyzer (101) to irradiate the process gas with the electromagnetic radiation (R1); extract the corresponding Raman spectrum (SR) from the detected measurement electromagnetic radiation (R2); and calculate the concentration of one or more chemical components in the process gas based on the Raman spectrum (SR).

11. A monitoring device (100) for refining metals in a steel plant, characterized in that, It includes: A gas analyzer (101) is configured to detect the concentration of one or more chemical components in process gases originating from secondary metallurgical processing; and a pressure detector (103) is configured to detect the ambient pressure corresponding to the surface of the molten metal pool (M). And a processing unit (102) configured to estimate in real time the concentration of one or more chemical components dissolved in the molten metal pool (M) by means of the concentration of one or more chemical components in the process gas and the pressure.

12. The device (100) according to claim 11, characterized in that, The analyzer (101) is a Raman spectroscopy gas analyzer.

13. The device (100) according to claim 11 or 12, characterized in that, The analyzer (101) includes a coupling element (136) that allows the excitation of electromagnetic radiation (R1) and the measurement of electromagnetic radiation (R2) to be performed by directly measuring the flow rate of the process gas in the process gas extraction line (29).

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